Having ran Astatic in the 1980's, and being one of the first people in the country to be licensed for the first audio equalization processes for room reinforcement systems, let me add my comments to the articulation and microphone discussion. The original D-104 was chosen by so many hams, as the crystal element was designed to emphasize the 300-3,000 hz range. Most articulation is added in the 2,000 to 3,000 hz area and the D-104 had a "bump" there. Also the D-104 had output (Hi-z) that could almost drive the modulators of the time with no pre-amp...Hi, Hi. First SSB rigs were designed to limit the response in that same range, so that mike was popular for the "new" SSBers. As Kenwood and others developed rigs that gave better response in the low end and low-z, dynamic mikes were now becoming popular, Bob Heil made his living by producing microphones that have a taylored response for typical rigs and applications. Bob's PR-40 is a professional, flat response mike, more suited for broadcast, than ham usage. It is much like a Sennhesier MD-441, in that there are certain characteristics that sound great for broadcast (and the PR-40 also has a very directional cardiod pattern). As the PR-40 has the typical dynamic proximity effect (get's boomy as you get closer to it), most hams have to taylor the response with some eq in the low end to remove this effect. I have tested the Flex-5k inputs with a noise generator and analyzer and it is flat as a pancake. That is why the PR-40 sounds great (some minor touch up of the 100-400 hz range) right in the front mike connector. In fact, after running my PR-40 through my DSP audio rack, the sound is not too different between the front panel 5K mike jack and my rack.You can have an articulate 100-3000hz SSB signal, so articulation and bandwidth are not tied together. The real problem is listener fatigue (as pointed out by the first gentleman in this chain). There have been many papers written over the years and published in the Audio Engineering Society Journal. I designed and ran the sound system for the AES meetings in L.A. for several years. Room acoustics (reverberation, multi path signals or echo), noise (huge listener fatigue occurs when the noise floor is within 10 db of signal), and our buddy articulation, are all key factors. Without a doubt, a wider bandwidth, higher fidelity signal, produces less listener fatigue. Years ago, we did some tests where we used just high frequency (300hz roll off) horns in sound reinforcement systems. We then added bass horn cabinets to the same installations. The difference in listener fatigue was huge. So, most importantly, in my audio tests and on air results of eqing an SSB signal, adding "presence" in the low end is essential to providing a signal that produces lower listening fatigue. Adding extra bandwidth in the high end is great (and I do it all the time where it does not interfere with others), but the low end presence is still the key!!! Harry W9BR
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